Texas Chainsaw Massacre
https://en.wikipedia.org/wiki/The_Texas_Chain_Saw_Massacre
http://www.the13thfloor.tv/2016/07/06/the-real-story-behind-the-texas-chainsaw-massacre-the-notorious-killer-ed-gein/
https://en.wikipedia.org/wiki/Sawney_Bean

The Entity
https://en.wikipedia.org/wiki/The_Entity
https://en.wikipedia.org/wiki/Doris_Bither_case
https://backpackerverse.com/doris-bither/

Open Water
https://en.wikipedia.org/wiki/Open_Water_(film)
https://en.wikipedia.org/wiki/Tom_and_Eileen_Lonergan

IT
https://en.wikipedia.org/wiki/It_(2017_film)
https://en.wikipedia.org/wiki/John_Wayne_Gacy

Wolf Creek
https://en.wikipedia.org/wiki/Wolf_Creek_(film)
https://en.wikipedia.org/wiki/Backpacker_murders
https://en.wikipedia.org/wiki/Murder_of_Peter_Falconio

Ravenous
https://en.wikipedia.org/wiki/Ravenous_(1999_film)
http://www.the13thfloor.tv/2016/11/02/the-true-story-that-inspired-the-movie-ravenous-cannibal-alfred-packer/

Fire in the Sky
https://en.wikipedia.org/wiki/Fire_in_the_Sky
https://en.wikipedia.org/wiki/Travis_Walton_UFO_incident

Annabelle
https://en.wikipedia.org/wiki/Annabelle_(film)
https://en.wikipedia.org/wiki/Annabelle_(doll)

The Strangers
https://en.wikipedia.org/wiki/The_Strangers_(2008_film)
https://en.wikipedia.org/wiki/Manson_Family
https://en.wikipedia.org/wiki/Tate_murders

The Exorcist
https://en.wikipedia.org/wiki/The_Exorcist_(film)
https://en.wikipedia.org/wiki/Exorcism_of_Roland_Doe